1. Field of the Invention
The present invention is generally related to an internal combustion engine fuel system and, more particularly, to a fuel system that has a fuel vapor separator which is vented to a separate container for preventing fuel spillage.
2. Description of the Prior Art
U.S. Pat. No. 5,103,793, which issued to Riese et al on Apr. 14, 1992, discloses a vapor separator for an internal combustion engine. The vapor separator assembly for an internal combustion engine includes a bowl member and a cover member. A fuel pump is located in the internal cavity of the bowl member and has an inlet located in the lower portion of the bowl cavity, for supplying fuel thereto. The, fuel pump is secured in position within the bowl member by engagement of the cover member with the fuel pump. The cover member includes a mounting portion for mounting a water separating filter element to the vapor separator assembly. The cover member includes structure for routing fuel from the discharge of the water separating filter element to the interior of the bowl member internal cavity. A compact arrangement is thus provided for the vapor separator, the fuel pump and the water separating filter, eliminating a number of hose connections between such components as well as facilitating assembly to the engine.
U.S. Pat. No. 5,203,306, which issued to Billingsley et al on Apr. 20, 1993, describes a fuel feed system for an internal combustion engine. The system includes a fuel pump, a vapor separator including a fuel chamber having an inlet and an outlet and being adapted to contain a supply of fuel, the vapor separator including a float valve and a passage for venting fuel vapor from the chamber when the supply of fuel is below a predetermined level, and a vapor pump communicating with the passage and a source of cyclically varying pressure for pumping fuel vapor from the vapor separator and to a location remote from the source of alternating pressure, the fuel vapor pump operating independently of the fuel pump.
U.S. Pat. No. 5,579,740, which issued to Cotton et al on Dec. 3, 1996, describes a fuel handling system for an internal combustion engine having a vapor separator for receiving fuel from a remote tank and a pump for delivering the fuel under high pressure to a fuel injector of the engine while providing vapor separation. The separator has an inlet for receiving fuel from the tank, an outlet for enabling fuel to be removed and delivered to the engine, at least one return for enabling fuel not used by the engine to be returned to the separator, and a vent for removing fuel vapor from a gas dome above a pool of liquid fuel within the separator. The inlet has a valve controlled by a float in the reservoir for admitting fuel to maintain the level of liquid fuel in the separator. To retard foaming and excessive vaporization of liquid fuel in the separator, the separator has a perforate baffle between any return and the liquid fuel pool. To prevent any stream of returned fuel, vapor and/or air from impinging against the fuel pool, the baffle preferably has a plurality of through openings which enable liquid fuel to pass through the baffle to the pool while deflecting any return stream away from the fuel pool. The baffle preferably extends outwardly to the separator sidewall for preventing any return stream from passing around the baffle and directly impinging against the liquid fuel while at least slightly pressurizing gas below the baffle for controlling vapor venting to the engine.
U.S. Pat. No. 5,229,766, which issued to Hargest on Jul. 20, 1993, describes a marine fuel tank pollution control apparatus. A marine craft includes a pollution control device for marine fuel tanks. The pollution control device includes a compartment for receiving fuel that leaves the fuel tank headed toward the vent via the vent line. The volume of the compartment desirably holds more fuel than would be contained in the volume of the length of the vent line that extends from the fuel tank to the vent. The compartment has an inlet that communicates with the fuel tank via the vent line. The compartment has an outlet that communicates with the vent via the vent line. The device includes a guide tube disposed within the compartment for preventing direct transmission of fuel to the vent. The device includes a float member disposed within the guide tube for detecting fuel in the vent line. The device includes an alarm circuit activated when the float member is located at a predetermined position within the guide tube. The device includes a lifting arm connected to the float member and enabling the float member to be lifted to a position where the operative alarm circuit should activate a signal.
U.S. Pat. No. 3,917,109, which issued to MacDonald on Nov. 4, 1975, describes an evaporative emission control system. A domed fuel tank carries a vapor-liquid separator in the domed portion with a single vent conduit extending from the vapor-liquid separator to the exterior of the tank.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
A fuel supply for a marine propulsion device made in accordance with the preferred embodiment of the present invention, comprises an engine having a crankshaft supported by the engine for rotation about a generally vertical axis. It also comprises a first fuel chamber having a first inlet conduit to receive liquid fuel from a fuel storage tank. A first outlet conduit is connected in fluid communication with the engine and a first vent is provided for allowing fuel vapors to flow out of the first fuel chamber.
A second fuel chamber has a second inlet conduit connected to the first vent of the first fuel chamber. The second fuel chamber also has a second vent for allowing fuel vapors to flow out of the second fuel chamber.
A valve, disposed within the second fuel chamber, is associated with the second vent for blocking the second vent when liquid fuel within the second fuel chamber exceeds a first predetermined amount. A sensor, disposed within the second fuel chamber, has an output signal which is representative of a condition in which the liquid fuel within the second fuel chamber exceeds a second predetermined amount. The first and second predetermined amounts can be the same amount in certain embodiments of the present invention.
The fuel system of the present invention can further comprise a first fuel pump for drawing liquid fuel from the fuel storage tank and for pumping the liquid fuel into the first fuel chamber. It can also comprise a second fuel pump for drawing fuel from the first fuel chamber and pumping the liquid fuel to the engine. In certain embodiments of the present invention, the; fuel system further comprises a fuel injector connected in fluid communication with the first fuel chamber and with the engine.
The valve of the present invention can comprise a float which is less dense than liquid fuel. The valve can also comprise a rounded surface which is movable into blocking association with the second vent in response to the liquid fuel within the second fuel chamber exceeding the first predetermined amount. Alternatively, a solenoid can be used to force a blocking element, such as the rounded or conical surface into blocking association with the vent. The second vent can be open to the atmosphere for allowing fuel vapors to flow out of the second fuel chamber.